Sandoval County, NM Accessory Structures: ADU Rules (2026)

Sandoval County's zoning ordinance recognizes two forms of accessory living space on a residential lot. A 'Guest House' is defined as a detached dwelling unit without a kitchen that sits on the same lot as, and is accessory to, a primary single-family dwelling (§ 6(B)(35)). 'In-Laws Quarters' is defined separately as an attached building with a kitchen similar to the primary dwelling unit (§ 6(B)(40)). In the RRA (Rural Residential/Agricultural) District, which covers most of unincorporated Sandoval County, both are permissive, by-right uses: item 2 of the district's use list allows one Guest House per lot, on the condition that all applicable New Mexico Environment Department liquid-waste requirements are met before construction and that all other provisions of the zoning ordinance are satisfied, and item 10 separately lists 'In-Law Quarters' as permissive (§ 9(1)).

Neither structure requires Zoning Commission review or a public hearing the way a Conditional Use does. District standards still apply to any accessory structure: residential buildings need a front setback of at least 20 feet and side and rear setbacks of at least 10 feet (§ 9(1)(D)), and new construction must go through the Zoning Officer's building-permit submission process, including a stamped floor plan and NMED liquid waste permit for new residential construction (§ 15(G)).